ArtTechDesignInc carries these LedgeLokr shelves with secret compartments. The top shelf remains level, while the bottom swings down to reveal the interior contents.
A user by the name of Thresher on Lumberjocks made this custom wooden box with a secret compartment behind the bottom drawer. Magnets are attached to the drawer and the secret compartment in a way that the drawer can be inserted upside down and pull the secret...
This custom built-in bench includes additional storage in the corner. The L-shaped bench is fitted inside a tiny home and has a trap door that opens in the corner to reveal the hidden storage compartment.